1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * Copyright (C) 2014 Filipe David Borba Manana <fdmanana@gmail.com> |
4 | */ |
5 | |
6 | #include <linux/hashtable.h> |
7 | #include <linux/xattr.h> |
8 | #include "messages.h" |
9 | #include "props.h" |
10 | #include "btrfs_inode.h" |
11 | #include "transaction.h" |
12 | #include "ctree.h" |
13 | #include "xattr.h" |
14 | #include "compression.h" |
15 | #include "space-info.h" |
16 | #include "fs.h" |
17 | #include "accessors.h" |
18 | #include "super.h" |
19 | #include "dir-item.h" |
20 | |
21 | #define BTRFS_PROP_HANDLERS_HT_BITS 8 |
22 | static DEFINE_HASHTABLE(prop_handlers_ht, BTRFS_PROP_HANDLERS_HT_BITS); |
23 | |
24 | struct prop_handler { |
25 | struct hlist_node node; |
26 | const char *xattr_name; |
27 | int (*validate)(const struct btrfs_inode *inode, const char *value, |
28 | size_t len); |
29 | int (*apply)(struct inode *inode, const char *value, size_t len); |
30 | const char *(*extract)(struct inode *inode); |
31 | bool (*ignore)(const struct btrfs_inode *inode); |
32 | int inheritable; |
33 | }; |
34 | |
35 | static const struct hlist_head *find_prop_handlers_by_hash(const u64 hash) |
36 | { |
37 | struct hlist_head *h; |
38 | |
39 | h = &prop_handlers_ht[hash_min(hash, BTRFS_PROP_HANDLERS_HT_BITS)]; |
40 | if (hlist_empty(h)) |
41 | return NULL; |
42 | |
43 | return h; |
44 | } |
45 | |
46 | static const struct prop_handler * |
47 | find_prop_handler(const char *name, |
48 | const struct hlist_head *handlers) |
49 | { |
50 | struct prop_handler *h; |
51 | |
52 | if (!handlers) { |
53 | u64 hash = btrfs_name_hash(name, strlen(name)); |
54 | |
55 | handlers = find_prop_handlers_by_hash(hash); |
56 | if (!handlers) |
57 | return NULL; |
58 | } |
59 | |
60 | hlist_for_each_entry(h, handlers, node) |
61 | if (!strcmp(h->xattr_name, name)) |
62 | return h; |
63 | |
64 | return NULL; |
65 | } |
66 | |
67 | int btrfs_validate_prop(const struct btrfs_inode *inode, const char *name, |
68 | const char *value, size_t value_len) |
69 | { |
70 | const struct prop_handler *handler; |
71 | |
72 | if (strlen(name) <= XATTR_BTRFS_PREFIX_LEN) |
73 | return -EINVAL; |
74 | |
75 | handler = find_prop_handler(name, NULL); |
76 | if (!handler) |
77 | return -EINVAL; |
78 | |
79 | if (value_len == 0) |
80 | return 0; |
81 | |
82 | return handler->validate(inode, value, value_len); |
83 | } |
84 | |
85 | /* |
86 | * Check if a property should be ignored (not set) for an inode. |
87 | * |
88 | * @inode: The target inode. |
89 | * @name: The property's name. |
90 | * |
91 | * The caller must be sure the given property name is valid, for example by |
92 | * having previously called btrfs_validate_prop(). |
93 | * |
94 | * Returns: true if the property should be ignored for the given inode |
95 | * false if the property must not be ignored for the given inode |
96 | */ |
97 | bool btrfs_ignore_prop(const struct btrfs_inode *inode, const char *name) |
98 | { |
99 | const struct prop_handler *handler; |
100 | |
101 | handler = find_prop_handler(name, NULL); |
102 | ASSERT(handler != NULL); |
103 | |
104 | return handler->ignore(inode); |
105 | } |
106 | |
107 | int btrfs_set_prop(struct btrfs_trans_handle *trans, struct inode *inode, |
108 | const char *name, const char *value, size_t value_len, |
109 | int flags) |
110 | { |
111 | const struct prop_handler *handler; |
112 | int ret; |
113 | |
114 | handler = find_prop_handler(name, NULL); |
115 | if (!handler) |
116 | return -EINVAL; |
117 | |
118 | if (value_len == 0) { |
119 | ret = btrfs_setxattr(trans, inode, name: handler->xattr_name, |
120 | NULL, size: 0, flags); |
121 | if (ret) |
122 | return ret; |
123 | |
124 | ret = handler->apply(inode, NULL, 0); |
125 | ASSERT(ret == 0); |
126 | |
127 | return ret; |
128 | } |
129 | |
130 | ret = btrfs_setxattr(trans, inode, name: handler->xattr_name, value, |
131 | size: value_len, flags); |
132 | if (ret) |
133 | return ret; |
134 | ret = handler->apply(inode, value, value_len); |
135 | if (ret) { |
136 | btrfs_setxattr(trans, inode, name: handler->xattr_name, NULL, |
137 | size: 0, flags); |
138 | return ret; |
139 | } |
140 | |
141 | set_bit(nr: BTRFS_INODE_HAS_PROPS, addr: &BTRFS_I(inode)->runtime_flags); |
142 | |
143 | return 0; |
144 | } |
145 | |
146 | static int iterate_object_props(struct btrfs_root *root, |
147 | struct btrfs_path *path, |
148 | u64 objectid, |
149 | void (*iterator)(void *, |
150 | const struct prop_handler *, |
151 | const char *, |
152 | size_t), |
153 | void *ctx) |
154 | { |
155 | int ret; |
156 | char *name_buf = NULL; |
157 | char *value_buf = NULL; |
158 | int name_buf_len = 0; |
159 | int value_buf_len = 0; |
160 | |
161 | while (1) { |
162 | struct btrfs_key key; |
163 | struct btrfs_dir_item *di; |
164 | struct extent_buffer *leaf; |
165 | u32 total_len, cur, this_len; |
166 | int slot; |
167 | const struct hlist_head *handlers; |
168 | |
169 | slot = path->slots[0]; |
170 | leaf = path->nodes[0]; |
171 | |
172 | if (slot >= btrfs_header_nritems(eb: leaf)) { |
173 | ret = btrfs_next_leaf(root, path); |
174 | if (ret < 0) |
175 | goto out; |
176 | else if (ret > 0) |
177 | break; |
178 | continue; |
179 | } |
180 | |
181 | btrfs_item_key_to_cpu(eb: leaf, cpu_key: &key, nr: slot); |
182 | if (key.objectid != objectid) |
183 | break; |
184 | if (key.type != BTRFS_XATTR_ITEM_KEY) |
185 | break; |
186 | |
187 | handlers = find_prop_handlers_by_hash(hash: key.offset); |
188 | if (!handlers) |
189 | goto next_slot; |
190 | |
191 | di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item); |
192 | cur = 0; |
193 | total_len = btrfs_item_size(eb: leaf, slot); |
194 | |
195 | while (cur < total_len) { |
196 | u32 name_len = btrfs_dir_name_len(eb: leaf, s: di); |
197 | u32 data_len = btrfs_dir_data_len(eb: leaf, s: di); |
198 | unsigned long name_ptr, data_ptr; |
199 | const struct prop_handler *handler; |
200 | |
201 | this_len = sizeof(*di) + name_len + data_len; |
202 | name_ptr = (unsigned long)(di + 1); |
203 | data_ptr = name_ptr + name_len; |
204 | |
205 | if (name_len <= XATTR_BTRFS_PREFIX_LEN || |
206 | memcmp_extent_buffer(eb: leaf, XATTR_BTRFS_PREFIX, |
207 | start: name_ptr, |
208 | XATTR_BTRFS_PREFIX_LEN)) |
209 | goto next_dir_item; |
210 | |
211 | if (name_len >= name_buf_len) { |
212 | kfree(objp: name_buf); |
213 | name_buf_len = name_len + 1; |
214 | name_buf = kmalloc(size: name_buf_len, GFP_NOFS); |
215 | if (!name_buf) { |
216 | ret = -ENOMEM; |
217 | goto out; |
218 | } |
219 | } |
220 | read_extent_buffer(eb: leaf, dst: name_buf, start: name_ptr, len: name_len); |
221 | name_buf[name_len] = '\0'; |
222 | |
223 | handler = find_prop_handler(name: name_buf, handlers); |
224 | if (!handler) |
225 | goto next_dir_item; |
226 | |
227 | if (data_len > value_buf_len) { |
228 | kfree(objp: value_buf); |
229 | value_buf_len = data_len; |
230 | value_buf = kmalloc(size: data_len, GFP_NOFS); |
231 | if (!value_buf) { |
232 | ret = -ENOMEM; |
233 | goto out; |
234 | } |
235 | } |
236 | read_extent_buffer(eb: leaf, dst: value_buf, start: data_ptr, len: data_len); |
237 | |
238 | iterator(ctx, handler, value_buf, data_len); |
239 | next_dir_item: |
240 | cur += this_len; |
241 | di = (struct btrfs_dir_item *)((char *) di + this_len); |
242 | } |
243 | |
244 | next_slot: |
245 | path->slots[0]++; |
246 | } |
247 | |
248 | ret = 0; |
249 | out: |
250 | btrfs_release_path(p: path); |
251 | kfree(objp: name_buf); |
252 | kfree(objp: value_buf); |
253 | |
254 | return ret; |
255 | } |
256 | |
257 | static void inode_prop_iterator(void *ctx, |
258 | const struct prop_handler *handler, |
259 | const char *value, |
260 | size_t len) |
261 | { |
262 | struct inode *inode = ctx; |
263 | struct btrfs_root *root = BTRFS_I(inode)->root; |
264 | int ret; |
265 | |
266 | ret = handler->apply(inode, value, len); |
267 | if (unlikely(ret)) |
268 | btrfs_warn(root->fs_info, |
269 | "error applying prop %s to ino %llu (root %llu): %d" , |
270 | handler->xattr_name, btrfs_ino(BTRFS_I(inode)), |
271 | root->root_key.objectid, ret); |
272 | else |
273 | set_bit(nr: BTRFS_INODE_HAS_PROPS, addr: &BTRFS_I(inode)->runtime_flags); |
274 | } |
275 | |
276 | int btrfs_load_inode_props(struct inode *inode, struct btrfs_path *path) |
277 | { |
278 | struct btrfs_root *root = BTRFS_I(inode)->root; |
279 | u64 ino = btrfs_ino(inode: BTRFS_I(inode)); |
280 | |
281 | return iterate_object_props(root, path, objectid: ino, iterator: inode_prop_iterator, ctx: inode); |
282 | } |
283 | |
284 | static int prop_compression_validate(const struct btrfs_inode *inode, |
285 | const char *value, size_t len) |
286 | { |
287 | if (!btrfs_inode_can_compress(inode)) |
288 | return -EINVAL; |
289 | |
290 | if (!value) |
291 | return 0; |
292 | |
293 | if (btrfs_compress_is_valid_type(str: value, len)) |
294 | return 0; |
295 | |
296 | if ((len == 2 && strncmp("no" , value, 2) == 0) || |
297 | (len == 4 && strncmp("none" , value, 4) == 0)) |
298 | return 0; |
299 | |
300 | return -EINVAL; |
301 | } |
302 | |
303 | static int prop_compression_apply(struct inode *inode, const char *value, |
304 | size_t len) |
305 | { |
306 | struct btrfs_fs_info *fs_info = inode_to_fs_info(inode); |
307 | int type; |
308 | |
309 | /* Reset to defaults */ |
310 | if (len == 0) { |
311 | BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS; |
312 | BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS; |
313 | BTRFS_I(inode)->prop_compress = BTRFS_COMPRESS_NONE; |
314 | return 0; |
315 | } |
316 | |
317 | /* Set NOCOMPRESS flag */ |
318 | if ((len == 2 && strncmp("no" , value, 2) == 0) || |
319 | (len == 4 && strncmp("none" , value, 4) == 0)) { |
320 | BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS; |
321 | BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS; |
322 | BTRFS_I(inode)->prop_compress = BTRFS_COMPRESS_NONE; |
323 | |
324 | return 0; |
325 | } |
326 | |
327 | if (!strncmp("lzo" , value, 3)) { |
328 | type = BTRFS_COMPRESS_LZO; |
329 | btrfs_set_fs_incompat(fs_info, COMPRESS_LZO); |
330 | } else if (!strncmp("zlib" , value, 4)) { |
331 | type = BTRFS_COMPRESS_ZLIB; |
332 | } else if (!strncmp("zstd" , value, 4)) { |
333 | type = BTRFS_COMPRESS_ZSTD; |
334 | btrfs_set_fs_incompat(fs_info, COMPRESS_ZSTD); |
335 | } else { |
336 | return -EINVAL; |
337 | } |
338 | |
339 | BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS; |
340 | BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS; |
341 | BTRFS_I(inode)->prop_compress = type; |
342 | |
343 | return 0; |
344 | } |
345 | |
346 | static bool prop_compression_ignore(const struct btrfs_inode *inode) |
347 | { |
348 | /* |
349 | * Compression only has effect for regular files, and for directories |
350 | * we set it just to propagate it to new files created inside them. |
351 | * Everything else (symlinks, devices, sockets, fifos) is pointless as |
352 | * it will do nothing, so don't waste metadata space on a compression |
353 | * xattr for anything that is neither a file nor a directory. |
354 | */ |
355 | if (!S_ISREG(inode->vfs_inode.i_mode) && |
356 | !S_ISDIR(inode->vfs_inode.i_mode)) |
357 | return true; |
358 | |
359 | return false; |
360 | } |
361 | |
362 | static const char *(struct inode *inode) |
363 | { |
364 | switch (BTRFS_I(inode)->prop_compress) { |
365 | case BTRFS_COMPRESS_ZLIB: |
366 | case BTRFS_COMPRESS_LZO: |
367 | case BTRFS_COMPRESS_ZSTD: |
368 | return btrfs_compress_type2str(type: BTRFS_I(inode)->prop_compress); |
369 | default: |
370 | break; |
371 | } |
372 | |
373 | return NULL; |
374 | } |
375 | |
376 | static struct prop_handler prop_handlers[] = { |
377 | { |
378 | .xattr_name = XATTR_BTRFS_PREFIX "compression" , |
379 | .validate = prop_compression_validate, |
380 | .apply = prop_compression_apply, |
381 | .extract = prop_compression_extract, |
382 | .ignore = prop_compression_ignore, |
383 | .inheritable = 1 |
384 | }, |
385 | }; |
386 | |
387 | int btrfs_inode_inherit_props(struct btrfs_trans_handle *trans, |
388 | struct inode *inode, struct inode *parent) |
389 | { |
390 | struct btrfs_root *root = BTRFS_I(inode)->root; |
391 | struct btrfs_fs_info *fs_info = root->fs_info; |
392 | int ret; |
393 | int i; |
394 | bool need_reserve = false; |
395 | |
396 | if (!test_bit(BTRFS_INODE_HAS_PROPS, |
397 | &BTRFS_I(parent)->runtime_flags)) |
398 | return 0; |
399 | |
400 | for (i = 0; i < ARRAY_SIZE(prop_handlers); i++) { |
401 | const struct prop_handler *h = &prop_handlers[i]; |
402 | const char *value; |
403 | u64 num_bytes = 0; |
404 | |
405 | if (!h->inheritable) |
406 | continue; |
407 | |
408 | if (h->ignore(BTRFS_I(inode))) |
409 | continue; |
410 | |
411 | value = h->extract(parent); |
412 | if (!value) |
413 | continue; |
414 | |
415 | /* |
416 | * This is not strictly necessary as the property should be |
417 | * valid, but in case it isn't, don't propagate it further. |
418 | */ |
419 | ret = h->validate(BTRFS_I(inode), value, strlen(value)); |
420 | if (ret) |
421 | continue; |
422 | |
423 | /* |
424 | * Currently callers should be reserving 1 item for properties, |
425 | * since we only have 1 property that we currently support. If |
426 | * we add more in the future we need to try and reserve more |
427 | * space for them. But we should also revisit how we do space |
428 | * reservations if we do add more properties in the future. |
429 | */ |
430 | if (need_reserve) { |
431 | num_bytes = btrfs_calc_insert_metadata_size(fs_info, num_items: 1); |
432 | ret = btrfs_block_rsv_add(fs_info, block_rsv: trans->block_rsv, |
433 | num_bytes, |
434 | flush: BTRFS_RESERVE_NO_FLUSH); |
435 | if (ret) |
436 | return ret; |
437 | } |
438 | |
439 | ret = btrfs_setxattr(trans, inode, name: h->xattr_name, value, |
440 | strlen(value), flags: 0); |
441 | if (!ret) { |
442 | ret = h->apply(inode, value, strlen(value)); |
443 | if (ret) |
444 | btrfs_setxattr(trans, inode, name: h->xattr_name, |
445 | NULL, size: 0, flags: 0); |
446 | else |
447 | set_bit(nr: BTRFS_INODE_HAS_PROPS, |
448 | addr: &BTRFS_I(inode)->runtime_flags); |
449 | } |
450 | |
451 | if (need_reserve) { |
452 | btrfs_block_rsv_release(fs_info, block_rsv: trans->block_rsv, |
453 | num_bytes, NULL); |
454 | if (ret) |
455 | return ret; |
456 | } |
457 | need_reserve = true; |
458 | } |
459 | |
460 | return 0; |
461 | } |
462 | |
463 | int __init btrfs_props_init(void) |
464 | { |
465 | int i; |
466 | |
467 | for (i = 0; i < ARRAY_SIZE(prop_handlers); i++) { |
468 | struct prop_handler *p = &prop_handlers[i]; |
469 | u64 h = btrfs_name_hash(name: p->xattr_name, strlen(p->xattr_name)); |
470 | |
471 | hash_add(prop_handlers_ht, &p->node, h); |
472 | } |
473 | return 0; |
474 | } |
475 | |
476 | |